UK Cover Design for ECHO
There's a lot of discussion there about the colors, the fonts used in the title, and the symbolism of the "skeleton leaf" on the cover. You may want to check it out.
UPDATE 2/6/09 6:30 pm: Diana announced today that the U.S. version of the cover is going to be a jewel-tone cover with a caltrop on it, but the background color will be black, not dark red. Look here for a picture of the proposed cover art. I think it looks fantastic, though it's quite different from the UK cover design. If you want to comment on the U.S. cover art, my latest blog entry on the subject is here.